Our multidisciplinary research group (Department of Physics, Electrical Engineering, Medicine Pathology) will continue to apply our pulmonary NMR techniques to the development of new pulmonary methods for physiologic and clinical exploration of pulmonary and cardiac questions. We will continue our investigations in normal lungs and in various experimental models of pulmonary edema, using excised unperfused lungs and living animals (rats and rabbits) We will: 1) develop and test NMR techniques for measuring lung water, its spatial and density distribution, and its behavior relative to the air/tissue interface. These studies will include determinations of the lung NMR relaxation times T1 and T2, to test the effects of various physiologic and pathologic factors, including regional lung water distribution, state of water (free water vs water bound to macromolecules), level of lung inflation, and pulmonary edema. 2) Develop and test mathematical (geometric) models for explaining the unique NMR behavior of inflated lung (internal sample-induced inhomogeneous broadening). These models will be applied to the simulation of pulmonary edema, especially of its effects on the alveolar air/tissue interface. We will utilize the tissue morphometric characteristics of lung specimens to calculate the NMR behavior predicted on the basis of our models and compare the predicted behavior with our NMR measurements. The basic research included in this proposal will further our understanding of the NMR behavior of lung and establish the feasibility of the application of our new techniques to clinical problems.